From European Patent Reference EP-A1-0 567 805, a hydraulic piston engine is known which has a number of axial cylinders. The cylinders are circumferentially arranged in a rotatable cylinder barrel. Each of the cylinders is provided with a channel, which alternatingly communicates with an inlet port or an outlet port in the end portion of a housing. In order to secure a sealing contact between the cylinder barrel and the housing in the area of the inlet and outlet ports, the cylinder barrel is biased along its rotational axis in the direction towards the inlet and outlet ports in the housing. This bias is accomplished by means of a compression spring which is positioned on a support pin. This support pin extends in the axial direction of the cylinder barrel and is supported against an angled plate. The angled plate is rotatable together with the input/output shaft of the engine. The rotation of the cylinder barrel is synchronized with the rotation of the input/output shaft by means of synchronizing means such as a tooth gear transmission.
The end portion of the housing of the engine is removed and remounted when it is desirable that the rotational direction of the engine be reversed. This is accomplished by rotating the end portion of the housing approximately 180xc2x0 such that the inlet and outlet ports shift positions. Such reversal is known from U. S. Pat. No. 4,934,253. When removing the end portion of the housing, the cylinder barrel is urged without control outwardly of the housing by means of the biasing force (spring), and can fall out of the housing if the engine is so positioned that the end portion is positioned downwardly of the housing. This results in that the engaging parts of the synchronizing means will come out of engagement with each other, which can cause problems when remounting the end portion of the housing. Further, the support pin can fall out of its position in the cylinder barrel and be loose when remounting the end portion of the housing.
The object of the present invention is to provide a hydraulic rotating axial piston engine of the above discussed type in which the cylinder barrel is prevented from coming out of its operating position when an end portion of the housing is removed. The present object is obtained by connecting the support pin at one end with the angled plate, and at the other end with the cylinder barrel.
The engine of the present invention has a housing enclosing a rotatable cylinder barrel. The cylinder barrel has a number of axial cylinders with a number of reciprocating pistons. The pistons reciprocate between two defined end positions, and cooperate with an angled plate in order to obtain the reciprocating movement. The cylinders have ports alternatingly acting as inlet and outlet ports, and the housing has at least one inlet and outlet channel. Each channel has a kidney-shaped port, facing towards the inlet and outlet ports of the cylinder barrel, and communicating with a number of the ports at the barrel. The cylinder barrel is rotatable relative to a first axis, which is inclined relative to a second axis of an input/output shaft. The angled plate is rotatable together with the input/output shaft around the second axis. The rotation of the cylinder barrel and the input/output shaft is synchronized by means of synchronizing means. The central support pin extends along the first axis between the angled plate and the cylinder barrel. The housing has at least two parts, one part of said housing positioning the input/output shaft and the second part including the kidney-shaped ports.
The second part of the housing including the kidney-shaped ports is removeable from the first part, and is remountable in a different rotational orientation relative to the first part such that the rotational direction of the engine can be reversed. To prevent the pin from falling out of the housing when the second part is removed, the pin has a spherical head at one end, which is received in a spherical recess in the angled plate; and a seat means at the other end which retains the other end of the pin within the cylinder base with only limited axial movement.
Further features of the present invention will become apparent to those skilled in the art upon reviewing the following specification and attached drawings.